test: add unit tests for HomeScreen to ensure proper rendering

Following TDD principles (RED-GREEN-REFACTOR):
- RED: Created failing tests for HomeScreen rendering
- Verify RED: Confirmed tests failed due to missing mocks
- GREEN: Added necessary mocks for all dependencies
- Verify GREEN: All 4 tests passing (4/4)

Tests cover:
- Title bar rendering with app name
- Category tabs rendering when data is loaded
- Template cards rendering when category has templates
- Loading state not showing when data is loaded

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app/(tabs)/__tests__/index.test.tsx

@@ -0,0 +1,134 @@
+import React from 'react'
+import { render, waitFor } from '@testing-library/react-native'
+import { SafeAreaProvider } from 'react-native-safe-area-context'
+import HomeScreen from '../index'
+
+// Mock expo-linear-gradient
+jest.mock('expo-linear-gradient', () => ({
+    LinearGradient: 'LinearGradient',
+}))
+
+// Mock expo-image
+jest.mock('expo-image', () => ({
+    Image: 'Image',
+}))
+
+// Mock expo-status-bar
+jest.mock('expo-status-bar', () => ({
+    StatusBar: 'StatusBar',
+}))
+
+// Mock icons
+jest.mock('@/components/icon', () => ({
+    DownArrowIcon: () => 'DownArrowIcon',
+    PointsIcon: () => 'PointsIcon',
+    SearchIcon: () => 'SearchIcon',
+}))
+
+// Mock components
+jest.mock('@/components/ErrorState', () => 'ErrorState')
+jest.mock('@/components/LoadingState', () => 'LoadingState')
+jest.mock('@/components/RefreshControl', () => 'RefreshControl')
+
+// Mock dependencies
+jest.mock('expo-router', () => ({
+    useLocalSearchParams: jest.fn(() => ({})),
+    useRouter: jest.fn(() => ({
+        push: jest.fn(),
+    })),
+}))
+
+jest.mock('react-i18next', () => ({
+    useTranslation: () => ({
+        t: (key: string) => key,
+    }),
+}))
+
+jest.mock('@/hooks/use-activates', () => ({
+    useActivates: jest.fn(() => ({
+        load: jest.fn(),
+        data: {
+            activities: [
+                {
+                    id: '1',
+                    title: 'Test Activity',
+                    desc: 'Test Description',
+                    coverUrl: 'https://example.com/image.jpg',
+                    link: '/test',
+                },
+            ],
+        },
+        error: null,
+    })),
+}))
+
+jest.mock('@/hooks/use-categories', () => ({
+    useCategories: jest.fn(() => ({
+        load: jest.fn(),
+        data: {
+            categories: [
+                {
+                    id: 'cat1',
+                    name: 'Test Category',
+                    templates: [
+                        {
+                            id: 'template1',
+                            title: 'Test Template',
+                            webpPreviewUrl: 'https://example.com/preview.webp',
+                            previewUrl: 'https://example.com/preview.jpg',
+                            coverImageUrl: 'https://example.com/cover.png',
+                            aspectRatio: '1:1',
+                        },
+                    ],
+                },
+            ],
+        },
+        loading: false,
+        error: null,
+    })),
+}))
+
+const renderWithProviders = (component: React.ReactElement) => {
+    return render(
+        <SafeAreaProvider initialMetrics={{
+            frame: { x: 0, y: 0, width: 375, height: 812 },
+            insets: { top: 44, left: 0, right: 0, bottom: 34 },
+        }}>
+            {component}
+        </SafeAreaProvider>
+    )
+}
+
+describe('HomeScreen', () => {
+    it('should render title bar with app name', async () => {
+        const { getByText } = renderWithProviders(<HomeScreen />)
+
+        await waitFor(() => {
+            expect(getByText('Popcore')).toBeTruthy()
+        })
+    })
+
+    it('should render category tabs when data is loaded', async () => {
+        const { getByText } = renderWithProviders(<HomeScreen />)
+
+        await waitFor(() => {
+            expect(getByText('Test Category')).toBeTruthy()
+        })
+    })
+
+    it('should render template cards when category has templates', async () => {
+        const { getByText } = renderWithProviders(<HomeScreen />)
+
+        await waitFor(() => {
+            expect(getByText('Test Template')).toBeTruthy()
+        })
+    })
+
+    it('should not show loading state when data is loaded', async () => {
+        const { queryByText } = renderWithProviders(<HomeScreen />)
+
+        await waitFor(() => {
+            expect(queryByText('加载中')).toBeNull()
+        })
+    })
+})